1. Field of the Invention
This invention relates to an apparatus and an associated method for rapidly and efficiently maintaining the desired lateral position of an elongated strip on a rotatable roll and also provides means for monitoring and controlling the tension on said strip.
2. Description of the Prior Art
It has long been known to store strip materials in coils and for various purposes to transfer the strip from a first coil to one or more second coils with the strip moving at a rapid rate between such coils. Numerous types of processing of the strip as it moves from a first coil to one or more second coils may be provided such as, for example, in the case of steel, galvanizing the strip. It is also known to slit the strip longitudinally so that a single coil strip moves from a first coil onto a plurality of smaller coils having strip of a reduced width as compared with the original strip. Any number of additional processes including coating of the strip, thermal treatment of the strip, laminating of the strip are known. Other examples of such processing lines are rolling mills and paper and plastic processing lines.
In such operations it is conventional to have one or more intermediate driven or idler rolls which serve to support the strip and maintain its movement in the desired direction. It is important that such strip be caused to track along the desired path of movement to resist unwanted deviations in the processing or treatment of the strip edges through physical contact with other components of the equipment.
U.S. Pat. No. 2,722,415 discloses an apparatus for guiding a sheet wherein the apparatus includes an axially moveable roll which is mounted for axial movement through interconnection with a vertical pivot shaft. The pivot shaft provides for rotation about an axis perpendicular to the general plane of travel of the sheet and, furthermore, provides only for single plane guiding of the sheet, i.e., the sheet travels between two spaced elements disposed in general parallelism in a common plane.
German Patent 2,407,842 discloses a strip guiding apparatus having a rotatable roll and a rotatable support means for rotating the roll. The support shaft remains vertical at all times while the strip may be offset to provide a wrap angle for the strip to effect the required friction of the strip on the roll.
It has also been known to employ devices, such as bridle rolls or pinch rolls, or other holdback or pulling means to facilitate maintaining the desired strip tension.
Despite the foregoing known means, there remains a very real and substantial need for improved, rapid acting automated systems that will effectively cause strip to track on rolls which are rotatably supporting the strip during movement without effecting unwanted edge strain or tension causing stretching of the strip edges and other undesirable results.